Comments On The Taxonomy And Geographic Distribution Of North American Part 2

_Comparisons._--From topotypes of _Clethrionomys gapperi wrangeli_, _C. g. solus_ differs as follows: dorsal stripe wider and slightly brighter; sides brighter; venter more heavily washed with Ochraceous-Tawny (heavy wash in all 13 _C. g. solus_ examined; in _C. g. wrangeli_ no wash in 11, slight wash in 16, and heavy wash in only one); nasals, alveolar extent of upper cheek-teeth and incisive foramina shorter; skull shallower when measured with tympanic bullae included; rostrum averages slightly broader.

From _C. g. phaeus_ of the adjacent mainland, _C. g. solus_ differs in: dorsal stripe slightly darker; ventral wash more prominent; tail shorter; skull smaller in all parts measured except that nasals are approximately the same length, auditory bullae notably smaller and teeth notably narrower.

_Measurements._--External and cranial measurements of adults are shown in table 1.

_Remarks._--Bailey (Proc. Biol. Soc. Was.h.i.+ngton, 11:120, May 13, 1897) referred 17 specimens from Loring to his newly named species, _E. wrangeli_ [= _Clethrionomys gapperi wrangeli_] but based his description on specimens from Wrangell Island. He pointed out (_loc. cit._) that all of the specimens from Loring had the "bellies strongly washed with buffy-ochraceous, while more than half of those from Wrangell have whitish bellies."

_Specimens examined._--Total, 13, all in the Biological Surveys Collection, U. S. National Museum, from the following localities: Alaska: Revillagigedo Island: Loring, 10; mouth of Fish Creek, Ketchikan, 3.

Clethrionomys gapperi stikinensis, new subspecies

_Type._--Male, adult, skin and skull, No. 30735, Museum of Vertebrate Zoology, University of California; from Stikine River at Great Glacier, British Columbia; obtained on August 13, 1919, by J.

Dixon; original number 7691.

_Range._--Known only from the lower Stikine River Valley of British Columbia and the Cleveland Peninsula of Alaska.

_Diagnosis._--A medium-sized, dark-colored member of the _gapperi_ group. Dorsal stripe wide, near Auburn with mixture of black-tipped hairs; sides and venter washed with Ochraceous-Tawny. Skull small; cheek-teeth narrow; auditory bullae relatively uninflated.

_Comparisons._--From topotypes of _Clethrionomys gapperi wrangeli_, _C. g. stikinensis_ differs as follows: dorsal stripe slightly wider and brighter; sides slightly duller (lacking the olivaceous wash of _C. g. wrangeli_); all cranial measurements taken averaging smaller except height of skull, which is approximately the same; alveolar length of upper tooth-row and length of incisive foramina notably shorter; auditory bullae less inflated; cheek-teeth much narrower.

From topotypes of _C. g. phaeus_, _C. g. stikinensis_ differs as follows: dorsal stripe and sides darker; auditory bullae less inflated; cheek-teeth narrower; skull smaller in most measurements taken (see table 1).

From topotypes of _C. g. solus_, _C. g. stikinensis_ differs as follows: dorsal stripe lighter (more tawny underwash); ventral wash of buffy much paler (especially noticeable around mouth and on throat); zygomatic and lambdoidal breadths greater; skull deeper; auditory bullae more inflated; cheek-teeth slightly heavier.

TABLE 1. _External and cranial measurements of Clethrionomys._

N u m L b e e n r s g e t o x h f C o o o i r n f n d L A B d s y Z a l r i i p l y m L v e n v e o g b e e u a c H i c b o d n o p d i e d i a m o g l p t s i u m T s a i t a e h i g a e o i t d h r r v h l n t l i a o e t s a H a c l o l t f m l i r f e o f o o e n b b n o r o f f a l d l r r n g t o r s e e e e a t h s a s e u n T f n a a s h t m k a r g a o g d d a r r i u c e t i o t t t l o o u n l h d h l t h h h s f w m a l

_Clethrionomys gapperi solus_, Loring

Male type 133 33 20 22.3 12.5 10.9 6.8 5.1 3.4 5.3 9.0 Male 5 av. 131 34 20 22 12.7 10.8 6.8 5.3 3.5 5.1 9.1 min. 128 33 19 21.8 12.5 10.5 6.7 5.1 3.3 5.0 8.9 max. 133 36 20 22.3 13.0 11.2 7.1 5.5 3.6 5.3 9.5 Female 5 av. 128 34 19 21.3 12.5 10.5 6.5 5.4 3.5 4.9 9.2 min. 124 31 19 20.9 12.3 10.3 6.0 5.2 3.3 4.8 8.9 max. 140 36 20 21.7 12.7 10.7 7.0 5.6 3.6 5.0 9.5

_Clethrionomys gapperi stikinensis_, Stikine River at Great Glacier

Male type 145 39 20 23.2 13.9 11.4 7.3 5.0 3.1 5.5 9.5 Male 4 av. 136 35 20 22.2 13.0 11.1 6.8 5.2 3.4 5.2 9.4 min. 132 33 19 21.5 12.3 10.7 6.5 5.0 3.1 5.1 9.1 max. 145 39 20 23.2 13.9 11.4 7.3 5.6 3.5 5.5 9.7 Female 7 av. 134 33 19 21.8 12.7^6* 10.9 7.0 5.4 3.4 5.1 9.5 min. 125 30 19 21.5 12.5 10.5 6.7 5.3 3.2 5.0 9.2 max. 147 35 20 22.2 12.9 11. 7.1 5.6 3.7 5.3 9.8

_Clethrionomys gapperi wrangeli_, Wrangell

Male 9 av. 139 36 19 23.4^8 13.3 11.4^8 7.3 .6 .6 .6 9.6^8 min. 130 31 18 22.9 13.0 10.9 7.1 5.5 3.3 5.4 9.2 max. 151 43 20 23.9 13.7 11.8 7.6 5.8 4.0 5.8 10.1 Female 16 av. 134 34 18^15 23.2 13.3 11.2^13 7.3 5.8 3.5 5.5 9.4 min. 123 28 17 22.4 12.6 10.7 6.9 5.5 3.2 5.2 9.0 max. 156 45 20 24.1 14.1 11.8 8.0 6.1 3.7 5.9 9.7

_Clethrionomys gapperi phaeus_, Chickamin River

Male 5 av. 148 47 20 23.0^4 13.7^4 11.3^4 7.5^4 5.3^4 3.5^4 5.3^4 9.7^3 min. 138 38 20 22.3 13.0 11.1 7.1 5.3 3.4 4.9 9.3 max. 159 51 21 23.8 14.6 11.8 7.7 5.6 3.8 5.6 10.0 Female 4 av. 153 49 20 23.1^3 13.4 11.2^3 7.6^3 5.2 3.7 5.3 9.6^3 min. 140 44 20 22.4 12.8 10.8 7.3 5.0 3.4 5.1 9.2 max. 164 56 20 24.2 13.6 11.4 7.7 5.3 3.9 5.5 9.8

*Superior numbers denote the number of individuals averaged.

_Measurements_.--External and cranial measurements of adults are given in table 1.

_Remarks_.--Morphologically _C. g. stikinensis_ shows greater resemblance to _C. g. solus_ of Revillagigedo Island, than to the geographically adjacent subspecies _C. g. wrangeli_ and _C. g. phaeus_.

Possibly the original stock of _C. g. solus_ was rafted to Revillagigedo Island from the Cleveland Peninsula.

_Specimens examined_.--Total, 29, all in the Museum of Vertebrate Zoology, University of California, distributed as follows: British Columbia: Stikine River at Great Glacier, 22; Stikine River at Flood Glacier, 3. Alaska: Bradfield Ca.n.a.l, 1; Helm Bay, 2.

Pitymys pinetorum scalopsoides (Audubon and Bachman)

1841. _Arvicola scalopsoides_ Audubon and Bachman, Proc. Acad. Nat.

Sci. Philadelphia, 1:97, type from Long Island, New York.

1912. _Pitymys pinetorum scalopsoides_ Miller, U. S. Nat. Mus.

Bull., 79:229, December 31.

Hanson (Trans. Wisconsin Acad. Sci., Arts, and Letters, 36:124, 1944) reported two pine mice from near Prairie du Sac, in Westpoint Towns.h.i.+p, Columbia County, Wisconsin, as _Pitymys pinetorum scalopsoides_ but cast doubt upon their subspecific ident.i.ty. He also reported pine mice from Blue Mounds, Dane County, Wisconsin. We have examined these specimens (Westpoint, Columbia County, 2--No. 544, skin only, UWDEZ, and No. 521, skin only, H. C. Hanson's private collection; Westpoint, Dane County, 1, No. 11620, UWZM; Vermont, Dane County, 2, Nos. 11674 and 11694, UWZM) and have compared them with topotypes of _P. p.

schmidti_, and with specimens of _P. p. nemoralis_ and _P. p.

scalopsoides_. The specimens from Columbia and Dane counties differ from _P. p. schmidti_ in the greater zygomatic breadth, and lesser height of skull. They differ from _P. p. nemoralis_ of comparable age in shorter tooth-row and generally smaller skull. The interorbital region, however, is wider. In all of the features mentioned above, the specimens in question agree with _Pitymys pinetorum scalopsoides_, to which subspecies they are here referred.

Microtus pennsylvanicus aztecus (Allen)

1893. _Arvicola (Mynomes) aztecus_ Allen, Bull. Amer. Mus. Nat.

Hist., 5:73, April 28, type from Aztec, 5900 ft., San Juan County, New Mexico.

Allen (_loc. cit._) described this species on the basis of two specimens from Aztec, New Mexico, and three from La Plata, New Mexico.

He characterized it as "Size large; pelage very full and soft; tail short; skull very narrow.

"Above grayish brown with a tinge of pale buff; fur blackish plumbeous beneath the surface, tipped with pale yellowish brown, and varied with longer, projecting, black-tipped hairs; below grayish white, the fur plumbeous beneath the surface and tipped with white, giving a whitish gray effect. Feet dusky; tail dusky brown above, dull white below."

Allen identified as this species "a large _Arvicola_ from Estes Park, Colorado, which I have before been unable to allocate. I am unable to find that it differs in any particular from the specimens from New Mexico." He pointed out also (_op. cit._:73-74) that "The type and only positively identified specimen of Baird's _Arvicola modesta_ [= _Microtus pennsylvanicus modestus_ (Baird)] from Sawatche Pa.s.s, Colorado, is a very young specimen in poor condition. An examination of a series of adult and young examples from the type locality will be necessary in order to determine its relations.h.i.+ps to _A. alticolus_ [= _Microtus longicaudus alticolus_ (Merriam)] and _A. aztecus_."

Bailey, in his revision of the American voles of the genus _Microtus_ (N. Amer. Fauna, 17:20), showed _Arvicola modesta_ Baird to be a subspecies of _Microtus pennsylvanicus_ but retained _Microtus aztecus_ (Allen) as a distinct species. In describing _M. aztecus_ he wrote "the size similar to _M. pennsylvanicus_, but with shorter tail and larger hindfoot; skull long; braincase narrow; interparietal long ..." and remarked that "_Microtus aztecus_ belongs to the _pennsylvanicus_ group. Externally it is not very different from _modestus_, but none of the specimens show any signs of intergradation; and the skull characters are so well marked that there seems no doubt of its full specific rank."

Subsequent to the publication of Allen's (_op. cit._) account and Bailey's account (_op. cit._), additional material was collected that helps to clarify the relations.h.i.+ps of _Microtus aztecus_. A comparison of six adult topotypes of _Microtus aztecus_ with a series of nine adults of _M. p. modestus_ from 1 mi. S, 2 mi. E Eagle Nest, 8100 ft., Colfax County, New Mexico, with three adults from 1-1/2 mi. E Mana.s.sa, Conejos County, Colorado, and with four adults from Saguache County, Colorado (all in KU), reveals that the supposed "well marked" external and cranial differences between the two forms are not nearly so evident as was indicated by Bailey.

The cranial differences that exist between these two forms (narrower nasals, slightly longer interparietal, slightly longer and narrower skull in _aztecus_) are evident only as averages. Although geographically intermediate specimens are lacking, the morphological differences between the two kinds of animals are of the degree and kind that separate subspecies, rather than species. We therefore judge _M.

aztecus_ (Allen) to be only subspecifically distinct from _M.

pennsylvanicus modestus_ and employ the name _Microtus pennsylvanicus aztecus_.

Microtus pennsylvanicus funebris (Dale)

1940. _Microtus pennsylvanicus funebris_ Dale, Jour. Mamm., 21:338, August 14, type from Coldstream, 1450 ft., 3-1/2 mi. SE Vernon, British Columbia.

Taylor and Shaw (Occas. Papers Charles R. Conner Mus., State College Was.h.i.+ngton, 2:24, December, 1929) list under _Microtus na.n.u.s_ [= _monta.n.u.s_] _canescens_ material from Calispell Peak, Was.h.i.+ngton.

Probably the basis for this record is a specimen in the Biological Surveys collection (adult male, 236474) taken on May 9, 1921, by G. G.

Cantwell, and labelled as Calispell Peak, 9 mi. W Locke, 3500 ft., Pend Oreille County. An examination (by Hall and Kelson) of the specimen discloses that it is of the species _Microtus pennsylvanicus_, and that it falls within the geographic range ascribed to the subspecies _Microtus pennsylvanicus funebris_ by Dalquest (Univ. Kansas Publ., Mus. Nat. Hist., 2:346, April 9, 1948).